1. Field of the Invention
The present invention relates to a transformer, and more particularly to a transformer that is easy to manufacture.
2. Description of Related Art
Transformers are widely used in many electrical devices. The transformers are able to change voltage from high to low or from low to high so transformers are a very important part in many electrical devices.
With reference to FIGS. 6, 7 and 8, a conventional transformer comprises a cover (30, 40), multiple pins (32, 43), coils (33, 44) and encapsulant (46).
The cover (30, 40) has a top, a top opening (not numbered) and a cavity (31, 41). The top opening is formed on the top of the cover (30, 40). The cavity (31, 41) is formed in the cover (30, 40) and communicates with the top opening of the cover (30, 40) and has a bottom and multiple optional through holes (42). The through holes (42) are formed through the bottom of the cover (40) and correspond to each other.
The pins (32, 43) are mounted in and protrude from the cover (30,40). In a first embodiment of the conventional transformer, the pins (32) protrude through the top opening in the cover (30). In a second embodiment, the pins (43) are mounted respectively in the through holes (42) through the bottom of the cover (40), extend into the cavity (41) and protrude from the bottom of the cavity (41).
The coils (33, 44) are located inside the cavity (31, 41) and have wires (34, 45). The wires (34, 45) connect the coils (33, 44) respectively to the pins (32, 43).
The encapsulant (46) fills the cavity (31, 41) in the cover (30, 40) to seal the top opening and the cavity (31, 41) and protect the coils (33, 44).
The encapsulant (46) keeps manufacturing the transformers from being less expensive. Furthermore, the encapsulant (46) must be removed totally to correct any internal problem with the transformers. Removing and replacing the encapsulant (46) keeps manufacturing the transformers from being easy.
To overcome the shortcomings, the present invention provides a transformer to obviate or mitigate the aforementioned problems.